


Comes with Strings attached

by rehliamonster



Series: Prostitute Sans Series [3]
Category: Undertale (Video Game)
Genre: BDSM, Bondage, Dom/sub, Ecto-Penis (Undertale), Ecto-Tongue (Undertale), Edging, F/M, Loss of Control, Oneshot, Plot What Plot/Porn Without Plot, Power Exchange, Prostitution, Puppeteering, Safewords, Sensitive bones, Sub Sans, Teasing, Voluntary Prostitution, sans is a prostitute, spiderbones, weird kinks
Language: English
Status: Completed
Published: 2018-05-24
Updated: 2018-05-24
Packaged: 2019-05-13 10:55:01
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,909
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/14747504
Author URL: https://archiveofourown.org/users/rehliamonster/pseuds/rehliamonster
Summary: Sans gets paid to play out more of a weird scenario together with Muffet.He still loves his job.





	Comes with Strings attached

**Author's Note:**

> [My Tumblr](https://rehliamonster.tumblr.com/)

“Come in, dearie~"

The invitation was a bit unnecessary, considering that Sans had been led into the darkness of the spiderlair already and so had technically been ‘in’ for at least five minutes, but he could still appreciate the politeness of it. 

“thanks.” He took the seat she offered, relishing how plush the upholstery felt. Muffet might be saving up most of her income to help her clan, but she didn’t skimp on the fabrics for sure. Everything was made of softest spidersilk. Well, she was right at the source of it.

The room they were in was relatively simple, a small rectangle with a single door and no windows, dark purple walls and a silvery floor, the ceiling shrouded in darkness. It contained the upholstered chair Sans was currently occupying, a chaise lounge where Muffet took her seat, and a small side table between the two topped with a doily and a tablet of drinks and sweets. They looked delicious, but Sans didn't take anything. He hadn't been offered to. 

“First, the rules?” Muffet asked, again more a formality than anything else. The fact that she had known who to ask in order to book him meant that she knew the process. How this worked. 

“i got three on top of the usual one,” Sans told her. He didn’t elaborate what the usual one was - she’d know already. Clients didn’t rat out customers and customers didn’t rat out clients, that was the understanding that all monsters involved in this agreed on. Anyone who broke this rule would never be able to participate in any way again, and would be shunned throughout the Underground on top of that for breaking the trust. It was a system that relied entirely on referrals, secret code-words, and knowing who offered and who bought what. Even though most monsters were at least vaguely aware that prostitutes existed and that their services were made use of, nobody on the outside would have the details unless invited in. An open secret where the details of those involved were kept close to the chest. As far as Sans knew, this rule had never really been broken, but it was good to have anyway, just in case.

“one, papyrus doesn’t find out about it,” he said. Perhaps redundant, but then also not - he didn’t want his brother to know about Sans’ job even through a referral. 

“Of course,” Muffet agreed easily. That one never caused any trouble - most monsters understood the desire to keep this a secret from family members. 

With Papyrus, most also assumed that Sans felt his brother was too naive to know about sexual things, even though Sans had different concerns. Paps was a grown adult and knew about sex, and that was fine. The thing was just that Papyrus was a huge romantic down to his soul and would probably try to find a date for Sans as soon as he learned about this job, assuming that Sans was longing for the smooches and the like. Sans didn’t want a date though. He wanted to lie back, be fucked raw without having to do a single lick of work, and then be paid for the experience. It was his absolute dream job, but he knew Papyrus would have a bit of trouble wrapping his head around the idea of liking paid sex a lot more than romance. Easier to just sidestep that whole discussion. 

“two, no pain or dangerous practices,” he continued. His HP were way too low to even consider it with a closely trusted partner, let alone with a monster he didn’t know very well that paid for his services. 

“Hmm, does that mean no bondage practices as well?” Muffet wondered, running her five eyes over his body thoughtfully.

“you can tie me up ‘n take control, that’s fine,” Sans shrugged. “but anything that might hurt me is a hard no.” 

“That will be acceptable,” Muffet nodded, seemingly satisfied by his explanation. Sans happened to know that she sometimes liked inflicting pain with the pleasure, based on the description a colleague had given him when he contemplated coming here or not, but he trusted her to respect his limits. She could be ruthless, sure, but ultimately she was very professional as long as nobody tried to harm her spiders. 

“finally, you do the work. i don’t care about topping or bottoming or whatever, but i’m not gonna exert myself.”

A brief moment of silence. 

This was the point where some monsters would try to argue or decide they didn’t want this after all, which was fine. After he had started this job to pay back the enormous amounts of debts he had accumulated on his various tabs, he had made sure to keep on top of things financially. He didn’t have any outstanding bills or anything left, so he could more than afford some clients walking out on him. He wondered if Muffet suspected that he paid back the debts he used to have with her by selling himself as well. Probably. 

“Oh, dearie~ That will be no problem at all. I think you’ll find that we match each other _very_ well in this regard,” Muffet replied, giggling delicately into one of her many hands. “Will I be allowed to surprise you, provided that I follow your other rules? It would enhance the fun for me.”

“sure,” Sans agreed. As long as she followed his rules, he didn’t mind going along with whatever else she planned. “does the usual green, yellow, red work for you as safe words?”

“Of course,” Muffet said. 

With that, the negotiation was done. True businesswoman that she was, Muffet made no fuss about paying him immediately, not trying to skip out or haggle the price down or anything like that. Like all prostitutes in the Underground, Sans kept his prices within a certain range, only charging extra for services he knew only he could perform, to make it fair for both sides. 

“You can undress while I prepare,” Muffet told him once the transaction was complete and the money safely stashed in his magical inventory. “I'll be back in a moment~”

With that, she left the chaise lounge and crawled up the wall until she vanished into the shadows. 

Sans began taking off his clothes, wondering what she was planning. He didn't take care to move slowly or make his strip appealing, since she hadn't asked him to. Based on how she had phrased things, he thought that she wanted him naked so the real fun could begin, and there was no reason to expend the effort on a sensual strip if it wasn't necessary. As soon as his clothes were off, piled on the back rest of the chair, he sat back down and waited patiently for Muffet to return. 

He didn't have to wait long. 

She lowered herself down to the floor in front of him on a long, thick rope of spidersilk, made up of what must be hundreds of individual strands, silvery and purple. There was no way she had spun all of those just now, they must have been prepared in advance. 

Interesting.

She had indicated she wanted to do bondage, but this hinted at something more elaborate than the usual variety. Shibari? Perhaps. Maybe she wanted to role play with him as her prey? Also possible.

Without a word, Muffet separated some of the strands out of the rope and began tying them to him. 

Some went to his arms, winding through his radius and ulna, tightened around his carpals, metacarpals and phalanges. The wispy strands tickled the gaps between his bones. Muffet repeated the action on his other arm and then moved on to his ribcage, tying strings around his spine, his clavicles, his thoracic vertebrae and then downwards. 

“Tell me if you're uncomfortable, dearie~” Muffet instructed him as she bound several strings to his pelvis. Her eyes were glinting though, clearly taking pleasure from his curious look, from the fact that he didn’t know what was to come.

“i’m good,” he told her, keeping his eyes on the strings for now. “green.”

She nodded in satisfaction and lowered herself down to finish, binding his legs and metatarsals.

The strings really weren't uncomfortable, didn't cut into his bones too sharply. They wrapped around him like a caress even though tightened, tickling and stimulating rather than hurting him. He felt held by them, almost safe, especially since they didn't tie him down or otherwise restricted his movements. In fact, he was still free to move however he liked, could tilt his head and his limbs easily. All the strings did was lead from his body up into the shadows of the ceiling and then, it seemed, back down to Muffet's two lowest hands, like…

“oh,” he blurted out, at the same moment as Muffet twitched her fingers. 

His body moved without his input, standing up from his sitting position. It was the strangest sensation - he hadn't moved, he hadn't done _anything_ , and yet his body was taking step after step until he came to stand in front of Muffet, who was grinning fiendishly. He was so surprised, it didn’t even occur to him to try and move differently than how she directed him to.

“Relax, my little darling,” she purred, raising her two upper hands to caress his zygomatic arches while her middle ones began untying the ribbons of her dress. “It's easier if you do.”

“o-ok,” he stuttered, while the fingers of her lowest hands moved, to make him lean into her touch. 

“Green?” Muffet asked, squinting all five eyes at him after his stutter. 

Sans allowed himself to actually think about it for a second. He was bound and she made him move and to be honest, it was kind of creepy, to lose control of that. To move without any input from him, as if his body was no longer his own. 

But it was also interesting because it made him occupy a more active role without him actually having to work for it. Muffet had been correct in her assumption that they would match each other for this, because it allowed him to be lazy while she still got what she wanted. And the fact that she checked in with him added another layer of security; he might be bound and controlled by her strings, but ultimately he was still the one in control. She would respect his limits, would respect it if he used his safe word to tap out. 

That knowledge calmed him, and so he nodded and relaxed completely, allowing his body to go slack in the bonds. 

“green,” he confirmed. “i’ll let you know if it gets too much.”

“Good boy,” she crooned, petting his skull. “So short and cute and nice for me.”

They were technically of exactly the same height, but Sans didn't say anything. She and him were both smaller than most other monsters and he sort of understood the desire to feel taller than somebody else for once. 

Muffet made his hands reach up to assist her with undressing. He could feel the fabric under the tips of his phalanges, but couldn't linger on the sensation because the movements were not his own. He merely watched it happen. As if he caught a ride in somebody else's body for a while, getting to spy in on an intimate moment that had little to do with him. 

He relaxed further. 

He was getting paid for doing _nothing_. 

Muffet was doing all the actual work, moving him like a puppet on her strings, tugging and prodding his limbs into position to act out whatever fantasies she desired. All he had to do was to be present, and watch on. 

Stars, he loved his job. 

The feeling of fabric on his hands was replaced with that of warm, soft chitin as Muffet made him grab one of her modest breasts. 

“Mmmh, so forwards,” she sighed while his phalanges played with her nipples, completely without his input. 

“uh, yup,” he agreed, not sure if she wanted him to be vocal or not, and deciding to test it out. 

“Ahuhuhu, you really have no shame,” she laughed, making him pull the many frilly layers of her clothing off her body. She was left with nothing but a pair of stockings reaching up halfway to her thighs, held in place by more ribbons. These she didn't touch though. 

A tug on the strings caused him to push her back onto the chaise lounge, where she landed with her legs spread, her already dripping pussy on full display. 

“Make a cock,” Muffet commanded, staring at his pelvis with her two outer eyes while the inner three kept his face in view. 

Her shameless display and the constant, ticklish sensation of the strings tugging at his bones made it easy for him to comply. His magic rushed downwards easily, forming into a dick that was already mostly hard when it appeared. Interestingly, the strings had been tied in such a way that they cradled his cock, not obstructing his magic at all. Since she didn’t specify what she wanted, he went with what came naturally to him, something a little on the shorter and thicker side. 

Muffet liked her lips at the sight of it, sending a shiver of pride and pleasure down Sans’ spine. It wasn't that he needed the approval, but it certainly felt nice, to be so openly appreciated. 

She reached down and wrapped her left middle hand around it, getting a feeling for it, seeing how the weight would rest in her palm. Her hand felt warm and smooth on his ghostly flesh, and he grunted. She seemed to like that, based on her giggle. Instead of moving her hand, she tugged on the strings to make him rut into her hold. 

“ah…”

It was so strange. Usually he would hold still while his clients moved, only getting himself into position or meeting them. But this? It was like he was an entirely different monster, as if he wasn’t himself anymore. 

“So desperate,” Muffet sighed, squeezing his cock enough that he choked on any answer he might have given. 

His limbs moved, crawling onto the chaise lounge with her, having him kneel above her with his hands planted left and right to her head. Muffet had the lids of all five of her eyes lowered, giving him a bedroom look from below him. 

Sans felt that he was getting some idea what this was about, and did his best to return the look. 

Before he could fully comprehend what was happening, his teeth were pressed against her lips, a motion resembling a crushing kiss. He played along and licked his way into her mouth, which she accepted willingly with a soft moan. 

He was moved to lower himself on top of her, leaving his hands free to grope at her chest and her sides while his pelvis began rocking against her, his cock gliding over the soft, wet folds of her pussy and her clit. 

The movements were fast and rough, much harsher and quicker than anything he’d ever do by himself. He kept thinking that he should slow down, take it easy, but he wasn’t the one in control. She was. He could kiss her, and make some expressions, and that was it. That was all the participation he was capable of at the moment. His body would continue moving regardless, whether he wanted it to or not. It was happening regardless of his own thoughts. 

It was a situation that would have made him panic under any other circumstances, the idea of being unable to control himself while his body did things he’d never do by himself terrifying. 

In this case though, it was more arousing to him than he thought it would be. Feeling himself lose control in a sexual setting that ultimately _was_ controlled in spite of all appearances tickled something at his baser instincts. Additionally, knowing that Muffet was simply taking what she wanted from him, more so than any other client used him for their own pleasure… it was something he could honestly get off to as well. 

“ggnnnh…” 

A particularly slick glide of his cock caught against her opening, almost pushing him in, but she stopped just before it did. 

“muffet,” he whined, unable to control himself. He could feel the wet heat of her cunt clearly and he wanted it around him, but he couldn’t move. Not if she didn’t allow him to. When he tried even just twitching a little, all he ended up feeling was a tightening of the strings that were tied snug around his bones. She had the other other ends firmly in her lowest hands, not allowing the slightest bit of give, not allowing him even the fraction of movement of his own. 

“Begging won’t help you, my little puppet~" Muffet giggled, clearly amused by his undignified whimper. “In this net, you do what I want when I want it!”

He could see the greed sparking in her eyes, the sadistic desire to do more than just keep him trapped like a fly, to hurt him and hear him scream. To give in to her instincts and behave like the predatory spider she was. It would fuel her lust more, if she could. But he could also see her suppress it and her hands, when she touched him, were gentle. 

She slipped the fingers of her middle hands between his ribs, stroking over the spots where her silk was tied to him, and then massaging the inside of the bones where they were bare.

“oooh…”

He allowed the moan to slip past his teeth, ragged and desperate. Her two upper hands were meanwhile busy on his skull, using the opportunity of his open mouth to feel up his ectoplasmic tongue with open curiosity. 

In a fit of cheekiness that was in large parts fuelled by the frustrating sensation of his cock still pressing against her cunt without being able to get in, he liked languidly over her fingers, sucking them into his mouth to play with them there. He knew how soft his tongue felt to monsters with proper flesh, how the raw magic his ectoplasm was made of would spark and prickle against monster skin. 

_imagine what that would feel like inside you,_ his eyes said, meeting hers unblinkingly, half closed. _my cock is like that. imagine._

The shiver that ran over Muffet's whole form was viciously satisfying to watch. It worked and with a sudden yank on the strings that made him glad they were so soft and smooth, she manipulated him into position to enter her.

Good; this was more work than he'd put into an orgasm for a while. It skirted the edge of his rule a little, but not enough to cross.

Sinking into her wet heat was bliss. She felt tight, tighter than many other monsters he had been with, a natural consequence of being much close to him in size than other monsters. He didn't get to relish the sensation for very long. 

Muffet wasted no time, moving her fingers rhythmically and causing his body to follow along. Without any input from himself, his body began thrusting into her, rough and deep and hard, his ribcage pressing on her chest to keep her pinned down underneath him. 

“shit, oh shit,” he groaned out, unable to keep himself contained at the sudden and intense stimulation. It made his bones burn and his breath come in short, uneven gasps. He knew he wouldn't last long like this, and wondered about her. Her own sound was half a giggle and half a moan, her eyes rolling back. Her two middle hands were still clinging to his ribs, squeezing every now and then and sending bouts of blistering heat down his spine. The two upper hands had left his skull and were clenching into the upholstery of the chaise lounge, pulling at the fabric with no thought to potential damage. 

“Mmmh, Sans… n-no… so rough…”

The mumble was soft, almost shy, and didn't seem to be entirely directed at him. Her eyes had closed fully by now, her face contorted in what would look like pain if she wasn't also smiling, clearly far past usual arousal. 

It was a strange reaction, contrasting with her earlier statements about controlling his every move, but Sans understood it immediately. His experience at reading people had always come in handy while he had sex with clients, and his experience with the clients had in turn sharpened his observational skills by adding extra context and knowledge. It all came together easily in this instant as he looked down at Muffet from his position on top of her. 

She wasn't in control but she _was_ , he wasn't in control but he _was_. 

A mutual charade of dominance and submission. 

He leaned down and, in an action that came entirely from him, that she had not directed and had no control over at all, gently scraped his teeth over her neck, followed by licking the same path with his smooth, soft tongue. 

Allowing her to lose control completely, just once. 

“ _Sans!_ ”

Her scream was accompanied by a familiar convulsion of her body, a wild tremble as she arched up into him. The strings on him went slack, all control she had over him gone in an instant, and all six hands clung to him for dear life as she rode out her orgasm. 

Sans kept moving out of his own volition to get her through, although he really didn't manage to match the pacing she had set. 

He stuttered out slowly when the last few thrusts thankfully brought him over the edge as well, spilling himself inside her with an exhausted grunt. The magic of his come felt sticky and hot against the head of his cock, slowly sinking into the flesh of her cunt to mingle with the magic of her own body. It would give her a boost for an hour or so and then fade without a trace. 

“Ah… thank you,” Muffet told him, her speech slightly hazy with post-coital bliss. 

“good guess?”

“Very,” she giggled. “This was a good referral.”

They untangled themselves from each the slowly and Muffet began helping him untie all the strings she had tied to his bones. 

“this was interesting,” he commented as he replayed the events of the past hour or so to himself, his breath almost hitching when she pulled on a strand of silk and made it glide over the inside of one his ribs, so smooth and soft. “felt good.”

“Ahuhuhu~ I'm glad you liked it, dearie.” She was already pulling her dress back on, busying herself with getting the many layers and ribbons back in order. It didn’t take long for that one moment of deliberately orchestrated vulnerability to fade. 

It was kind of sad, in his opinion. She should allow herself to relax more. 

“anything else I can do for you?” He asked, giving her a certain look when she turned back to him ready to dismiss him before he even really finished. “i might know someone who would be willing to do the bondage _and_ the pain.”

Muffet looked delighted at the prospect. And despite the fact that Sans told her it wasn’t necessary, she shooed him out with an extra piece of gold for the referral.


End file.
